A item I sent has been returned to me undelivered. What to do?

[Tobermory]

I sent an item on 31st March, it was sent signed for. It has just been delivered back to me, obviously person was not home when they tried to deliver, it has a red sticker stating 'not called for'.

What to do?
Am I resaonable to expect the buyer to pay for postage a second time?

maybe contact them and find out why they didn't go and collect it then decide what's best to do?

Thanks Hecates.
I have already sent an email so will see what the response is.

Tobermory, I'd be interested to hear the outcome for you, because we've just had the same thing happen today.

SOMETIMES royal mail don't put cards through....BUT they keep recorded for 7 days (Ithink) so surely the buyer would have contacted you to see if you had posted it or not if that had happened?